Winter experiment planned in the Antarctic ice

The research vessel Polarstern leaves for the South Polar Sea on an 18-month long expedition.

Bremerhaven, 26 October 2012. The research ship POLARSTERN sets off in the early morning hours of 27 October 2012 for an unusual expedition to the Antarctic. This time the ship will not be returning to Bremerhaven as usual at the end of the Antarctic summer, but will be spending the winter in the South Polar Sea for research purposes. There are only a few ships throughout the world with which scientists can risk a winter expedition of this type in the Antarctic.

The so-called winter experiment is the climax of an 18-month long expedition in the southern hemisphere and will take the ship, its crew and the 54 scientists on board from Cape Town, South Africa to the Antarctic Weddell Sea. "We wish to investigate two fundamental research questions during this trip. The first one is which mechanisms bring the ecosystem of the South Polar Sea back to life after the long, cold and extremely dark winter? And secondly, why does the spread of the Antarctic sea ice increase slightly whilst the sea ice cover in the Arctic is constantly on the retreat?", explains the chief scientist Prof. Dr. Peter Lemke from the Alfred Wegener Institute for Polar and Marine Research in the Helmholtz Association.

Up to now scientists have not had enough data to answer these questions because the winter in the Weddell Sea is one of persistently long darkness, very strong winds and temperatures of up to minus 40 degrees Celsius. "Several severe storms per week are not rare at this time of year and are, of course, one of the reasons why hardly no ships stay in the Antarctic in winter", explains Peter Lemke.

The physicist and climate expert has already led one winter experiment of the POLARSTERN in 1992. During its fourth winter cruise in total, 21 years later, the ship will follow virtually the same route. However, the research approach this time is far more interdisciplinary: "During this expedition we will have scientists from all major scientific disciplines on board because we wish to tackle our two main questions in close cooperation and be able to answer the questions as comprehensively as possible at the end of the expedition", according to Peter Lemke.

For the research icebreaker POLARSTERN the coming winter cruise will be the fifth of this type. The last time the ship spent the winter months of 2006 in the Weddell Sea. "During the expedition at that time we learned that the biology in the sea and ice is already in full swing in September and October, i.e. in the middle of the Antarctic winter, and the question to arise was what exactly causes the start of the ecosystem into the new season?", says Peter Lemke.

This time the scientists are travelling earlier to the frozen Weddell Sea: "We wish to use the darkness of the polar night so as to travel into the spring from the south more or less with the rising sun and to see how the ecosystem starts the new season", explains Peter Lemke.

However, before Polarstern starts out on its winter experiment on 8 June 2013 in Cape Town, the ship has five other cruise legs. On the first leg, the transfer from Bremerhaven to Cape Town, some 30 young scientists from eleven different universities and research institutes will have the opportunity to collect data and samples for an interdisciplinary research and training programme called "Pelagic Biodiversity of the Atlantic Ocean". Following this the ship will head for the Atka Bay in the Weddell Sea to unload new snow vehicles, spare parts and the annual rations of food and fuel for the Neumayer III research station.

A so-called ice digger is on board for the first time which is to be used for research on huge ice floes. Contrary to traditional construction vehicles, the machine measuring around one times two metres does not have an excavator bucket but is equipped with an ice drill. The ice digger is to drill around 80 centimetre wide holes in the ice which then serve the research divers as starting point for investigations below the ice.

Notes for Editors:

The 18-month expedition is divided into ten cruise legs. A complete schedule is available on the internet at <www.awi.de/en/infrastructure/ships/polarstern/schedule_rv_polarstern/>. Excerpts from a lengthy video interview (in German language) with Professor Dr Peter Lemke is available at <www.youtube.com/watch?v=VCTlz8P--XM&feature=plcp>. Please find printable images in the online version of this press release at <www.awi.de/en/news/press_releases/>.

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The Alfred Wegener Institute conducts research in the Arctic, Antarctic and in the high and mid-latitude oceans. The Institute coordinates German polar research and provides important infrastructure such as the research icebreaker Polarstern and stations in the Arctic and Antarctic to the international scientific world. The Alfred Wegener Institute is one of the 18 research centres of the Helmholtz Association, the largest scientific organisation in Germany.